Governing mechanism for mixed-pressure turbines.



W. KiESER. GOVERNING MECHANXSM FOR MIXED PRESSURE TURBINES.

APPLICAUON HLED JAN-18. i915.

Patented. Aug. 17, 1915 Inventor; WaLtZ "K 3 es by: His

5 e s 5 e n w W wig-hie ED SATES 1 FER KIESER, OF CHARLQMENB'JEG, GERMANY, ASSIGETGLE T8 GENERAL ELEGTRIG COMPANY, A CQRPORATION 935' NEW GOVERNING FOB returnees-sense ELURBINES $1011 of Letters Patent P i;

Aug. 17,

Application filled f'snuury 15, 1915. Serial 30. 2,998.

T oil 20220222 it may concern Be it lmown that I, WALTER Knzssn a citizen of the Swiss Republic, residing at Uharlottenhurg, Germany, have invented certain new and useful lm rovements in Governing Mechanism for keel-Pressure Turbines, of which the following is a specification. t

The present invention relates to gover ing mechanism for mixed pressure turbines in which the admission valve means for the high and low 7 the same sense in response to the control of a speed governor and in the opposite sense in response to the control of a pressure regulator, that is to say one valve means opens while the other closes.

My improvement comprises in a mechanism of the addition of means whereby the travel of the pressure regulator is limited or controlled by the position of the speed governor.

in the accompanying drawmg, Figure 1 is a diagrammatic sectional view of a mixed pressure turbine embodying the invention, and Fig. 2 is a view illustrating the governing devices diagrammatically.

The turbine has a high receiving steam from apipe 2 controlled by a valve 3. The low pressure Wheels 4 are supplied'with steam from any suitable low pressure source, cumulator connected to the pipe 5. A valve 6 controls the admission of the low pres sure steam to the Wheels 4. A speed governor l of any approved type and driven by the turbine, controls the valves 3 and 6 through a system of levers and links and servomotors in such manner that both valves are operated in the same direction. To the main floating lever S to which the speed gov: erncr is connected, :1 pressure-responsive device 9 is also connected, at'such a point that it causes the valves3 and 6 to be operated in opposite directions. A pipe 10 connects the pressure regulator with the receiver or accumulator for low pressure steam.

through a lever 12 con- 8, so that its piston comes sired opening of the high pressure valve 3. This: scrvomotor determines to What extent "ure regulator shall move in case i of low pressure steam increases.

$11G servomotor has 21 pressure sources are moved in general character-described the later 9 Will engage its collar or pressure Wheel 1 such as a receiver or ac-V Preferably the lever 12 or the piston-rod of collar 13 above which.

an eye lllits loosely on the rod; said eye being connected to the movable abutment I oi the pressure regulator. When said reg-u lator acts, the eye moves freely until it brings up against the collar and arrests further movement of the pressure regulator,

It will thus be seen that the lower end po sition of the piston of the regulator 9 is determined by the bottom wall of the cylinder and that the upper end position of the pis ton is determined by the speed governor 7 through the cooperation of the servo-motor 11. Therefore, as a higher or lower position is determined by the governor for the pistonof the servo-motor and the collar 13 the two arm leve1g15 which moves about a fixed :"ulcruniand is moved by the pressure regustop 13 earlier or later so that further upward move ment ofthe piston and rod of said regulator are prevented. Inasmuch as the eye 14 on. lever 15 slides freely on the piston rod carrying the collar 13 it follows that the piston of the regulator 9 can move freely downward as the pressure of the fluid admitted b the pipe 10 decreases. By reason of the arrangement described a limitation of the movement of the pressure regulator is ob ained Without chan ing the tension of the spring in the regulator.

A diam-am illustration the principle of pressure valve 6 are operated by servou1otors controlled by the speed governor 7 thrl'iugzh a floating lever 9 connected at one end by a rod 9 to the movable abutment of the pressure regulator A. lever 15. fulcruzued at c, is pivoted to the link l6 which connects the speed governor with the float ing lever 8. At the free end of the lever 15 is a pin 17 working in a long loop 18 forming part of the rod 9. The pin serves as a stop for the loop and forms a lost mo tion device which allows the pressure rc ulator, (luring pressure changes, a greater or smaller freedom of motion. depending upon the position of the speed governor.

Suppose the machine is Working with high pressure steam at half load. which corresponds to the position a t u oi the lever S. The position of the lever 15 is then u 20 -50, if the p sure or the exhaust steam in the accumulator rises suddenly, the pressure regulator lifts the rod 9 and turns the lever 8 about the point t. The pin 17, however, checks the upward movement of the rod 9? when the bottom of the loop reaches the point a, so that ;I/ t z is the new position of the lever 8, and an overrcgulation, with a corresponding changing speed, is avoided.

The diagram also illustrates the ditliculties experienced with the previous arrangements of valves and controlling devices. reterred to at the beginning of this specification. Suppose the position of the floating lever 8, shown in the heavy line, to be that determined by the speed governor at no load and with only high pressure steam operation. Now with this position of the gov ernor, when the exhaust steam pressure rises and the pressure regulator tends accordingly to efi'ect a change from high pressure to low pressure operation; then, with the arrangement heretofore in use, the lever 8 first turned about the pivot h and took the position i 71, 7a. Inthis position, however. the machine would race, so that the speed governor would partially shut the'low pressure valve, which would lead to a position Z m of the lever 8. From this it will be seen that the high pressure valve wouldhave to have a considerable dead path and be provided with proper overlap.

in accordance with the provisions of the patent statutes, 1 have described the principle of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereofrbut I desire to have it understood that the appai-zita s shown is only illustrative, and that the ingention can mean \Vhat I claim as new and desire to secure by Letters Patent of the United States, is,

1. The combination with a mixed pressure turbine, of a speed governor and a pressure regulator therefor, and means for limiting the travel of the premure regulator according to the position of the speed governor.

2. The combination with a mixed pressure turbine, of a speed governor and a pressure regulator therefor, a floating lever to which the governor and the regulator are conbe carried out by other neoted,-and means ccn'trolledby said fioa-t-' ing lever for limiting the travel of the pressure regulator according to the position of the speedgovernor. 1

3. The combination with a mixed pressure turb1ne, of a speed governor and a pressure regulator therefor, a floating lever to which the governor and the regulator are connected, and a ost motion device controlled by said floating lever for limiting the t 'avel of the pressure regulator according to the position of the speed governor.

4. The combination with a mixedpreshave to 'come into play to controlling the valves, a pressure 7 sure .turbine,.

sure thrbine, of a speed governor and a pressure regulator therefor, a floating lever to which the speed governor and the pressure regulator are connected, a second lever actuated by said floating lever, and a device moving with the pressure regulator and adapted to strike and be checked by said second lever.

In a governing device for mixed pressure steam machines, in which the live steam inlet valve means and the exhaust steam governing valve means are moved by a speed regulator in the same sense and, depending on a pressure regulator, in opposite senses, the limiting of the travel of the pressure regulator-being iesponsive to the position of the speed regulator.

6. The combination with a mixed pressure turbine, of valves admitting high and low pressure motive fluid to the,turbine, a 8 speed governor driven bythe turbine for controlling the valves, a pressure regulator for modifying the action of the governor on one of the valves, and a means for restricting the action of the regulator which is con- 9 trolled by the speed governor.

7. The combination with a mixed pres sure turbine, of valves admitting high and low 'pressure motive fluid to the turbine, a

speed governor driven by the turbine for 9 regulator forfl modifying the act-ion of the governor on one of the valves which comprises relatively movable members subject to the action of low pressure motive fluid, and a stop-for 1 one of said members which is adjustable in response to movements of the speed governor.

8. The combination with a mixed pressure turbine, of valves admitting high and 1 low pressure motive fluid to the turbine, a speed governor driven by the turbine for causing the valves to move in the same sense in response to speed variations, a regulator for causing the valves to move in the op- 1 posite sense under variations in fluid pressure, anda means responsive to the control of the speed governor for'limiting the range of action of the regulator.

9. The combination with a mixed pres- 1 of valves admittingvhigh and low pressure motive fluid to the turbine, a speed governor driven by the turbine for causing. the valves to move ,in the same sense in response to spced'variations, a regulator for causing the valves to move-in the opposite sense under variations in fluid pressure,

I a servo-motor for changing the position of Zil 1,1so,os2 V a controlling the valves, :1 main floating lever which is coimectell to both viilves, a pressure regulator that is also connected to the lever, an auxiliary flouting lever which is connected to a moving member of the regulator, 21 servo-motor which moves a stop that limits the range of auction of the regulator, and means controlling the servo-motor in responseto the-action of the governor.

11. Th8 C fllllllilliitloll with a mixed pressure turbine, of valves controlling the 1dfmission of high and low pressure fluid to the turbine, a governor that controls said valves, :1 main floating lever that is connected to both valves, :1 pressure regulator which moves in response to changes of pressure of the lovv pressure source of supply, an nusihziry flouting lever that is ,LOXlIlQCtECl to 21 movable member of the regulator. a servomotor which moves a stop that limits the range of action of the regulator. and a means connecting the pilot valve of the servo-n1otor with the nniin flouting lever, the governor and the piston of said motor.

In witness whereof. I have hereunto set nrv hand this second (lay of January, 1915.

WVALTER KIESER. Witnesses 'ILLY Xzmuxx, Eexs'r Horn: 

